The wind that runs the island

The meltemi wind in Santorini, explained

8 min read

The meltemi is a dry northerly wind that dominates the Cyclades in summer. It blows mainly from June to September, occasionally from late May into October, and is near-continuous through July and August. Typical strength is Force 5 to 6, gusting harder. It builds through the day and usually eases around sunset.

Santorini is a windy island. Not occasionally windy, not windy in bad years — windy as a baseline condition, and everything anyone does on the water here is organised around that fact. This is the wind that does it, and what it means for a day on a boat.

What the meltemi is

The meltemi is a dry northerly wind that sets up over the Aegean in summer, driven by the pressure difference between a high over the Balkans and a low over south-west Asia. It arrives from the north or north-west, it is dry rather than damp, and it is remarkably persistent.

It is not a storm. That is the thing most visitors get wrong. Storms come and go in hours. A meltemi episode settles in, blows all day, drops back at night, and does it again the next morning. Sailingissues.com describes episodes that persevere through the night and repeat for many days, sometimes as long as ten (seen 25 August 2026).

It also has almost nothing to do with the weather forecast a holidaymaker reads. Meltemi days are usually cloudless, hot and bright. The sky tells you nothing at all. Only the sea does.

The daily rhythm

The meltemi has a shape to its day, and it is the single most useful thing to understand before you pick a departure time.

Overnight and early morning it is at its weakest. The land has cooled, the thermal contribution has gone, and the water in the caldera can be glass at 08:00.

It fills in from late morning. Sailingissues.com puts the usual onset in the early afternoon, reaching Force 4 to 5, which is 11 to 21 knots (seen 25 August 2026).

Mid-afternoon is the peak. This is when the sea outside the rim builds and when the north and east coasts of the island become unusable for small boats.

It eases at sunset. Not always, and not to nothing, but the classic pattern is a wind that dies as the light goes. That is why a sunset cruise can start in a stiff breeze and finish in near calm.

That rhythm is why our morning departure sits at 10:00 and our sunset departure at 15:00. It is also why, on the same day in July, the 10:00 boat can be flat and the 15:00 boat lively. Both are normal.

The numbers

Month by month: wind, water and what it does to a cruise

Sea temperatures are the Santorini monthly averages published by Climates to Travel (seen 25 August 2026). Wind descriptions are the consensus of the sailing sources listed below. This is climatology, not a forecast — any single day in August can be flat, and any single day in June can be unworkable.

Month	Typical wind	Sea	What it usually means for a boat day
April	Settling after winter. Northerlies begin to organise. Mostly Force 3 to 5.	16.5 °C	The first workable weeks. Cancellations are still normal, especially in the first half. The water is cold enough that few people swim for long.
May	Mostly settled. Early meltemi episodes are possible. Force 3 to 5, occasionally 6.	18.5 °C	A good operating month. Light traffic on the water, long comfortable days, and a sea still cool for the hot springs.
June	The meltemi establishes from about mid-month, usually weaker than what follows. Often Force 4 or under early, 5 to 6 later.	22.0 °C	Generally reliable. Afternoon build is the pattern to watch. Latest sunsets of the year, so the sunset cruise runs longest.
July	Peak meltemi. North to north-west, can blow for days on end. Force 4 to 7, gusting 8.	23.5 °C	Windiest operating month alongside August. Morning departures are materially more comfortable than afternoons. Most rerouting happens now.
August	Peak meltemi. The same pattern, sustained. Force 4 to 7, gusting 8.	24.5 °C	Warmest water of the year and the roughest average afternoons. North-coast beaches are often unusable. Book early in your stay and keep a spare day.
September	The meltemi weakens through the month, often not exceeding Force 4 late on. Mostly Force 4 to 5.	24.0 °C	Frequently the best combination on the island: warm sea, calmer afternoons, thinner crowds. Sunset moves 43 minutes earlier between mid-August and mid-September.
October	The meltemi can still appear. Southerlies return. Force 3 to 6, occasionally 7.	22.0 °C	Workable and often lovely, but weather-dependent. Clocks go back on 25 October 2026, which pulls sunset back an hour on the calendar.

November to March sits outside the season. Winter depressions bring Force 5 to 8 in frontal passages, and long swell wraps into the caldera from the west and south-west. Wind sources: sailingissues.com, kavas.com, davestravelpages.com and igohellas.com, all seen 25 August 2026.

The baseline nobody publishes

Operators tend to write about calm seas. Here is the actual number instead.

Windfinder's long-run statistics for Santorini airport, from observations spanning November 2000 to July 2026, give a mean wind of north-west at 12 knots, with mean gusts of 29 knots (seen 25 August 2026).

That is a genuinely breezy island by Mediterranean standards, averaged across every month of a quarter century. It is the honest baseline to start from, and it is why the captain's morning call exists at all.

Inside the caldera versus outside it

This is the part that surprises people. On a windy day, the caldera is usually the calm option.

The basin is ringed on three sides by cliffs standing up to about 300 m. A northerly meltemi hits that wall and much of it goes over the top. The water inside can be workable when the open sea outside is not.

Direction matters more than speed. A northerly leaves the south coast — Red Beach, White Beach, Mesa Pigadia — comparatively sheltered. A southerly, the sorokada that arrives off North Africa, does the opposite: it makes the same south coast unworkable while the basin stays flatter.

That is why a single wind speed is a useless rule of thumb, and why igohellas.com warns explicitly against them in its Santorini wind guide (seen 25 August 2026). The right question is never how many knots. It is which coast, from which direction, and what the swell is already doing.

How to book around it

Take a morning slot in July and August. The 10:00 departure is the flattest water a Santorini summer offers. If somebody in your group is prone to seasickness, this is the whole answer — more on that in seasickness and sea conditions.

Book early in your stay, not on your last day. If the captain stands the boat down, a date on day two of a week gives you five chances to sail. A date on the morning of your flight gives you none.

Consider the shoulder months. May, June, September and early October give lighter wind, warm enough water and fewer boats in the same bay. September in particular pairs the warmest sea of the year with the calmest afternoons of the season. See the best month, month by month.

Do not read the sky. A meltemi day looks perfect from a hotel terrace. What decides your cruise is the sea, and you cannot see it from up there.

We do not publish a wind threshold

You will sometimes see operators quote a number — a knot count above which they never sail. We have not published one, and we are not going to invent one for this page.

The reason is in the section above. Twenty knots from the north with a settled sea is a normal working day. Twenty knots from the south with yesterday's swell still running is not. A single figure would be tidy and it would also be misleading.

What we can tell you is who decides and when: the captain, on the morning of your cruise. That process is written out in full in what happens if the wind comes up.

Ready when you are

Tell us your dates and we will tell you what the wind usually does

Send the week you are on the island. We will say plainly which departure we would put you on, and whether we would keep a spare day back.

Check availability & book

Call the harbour office+30 698 977 1888

Common questions

How windy is Santorini on average?

Windfinder's record for Santorini airport, from observations spanning November 2000 to July 2026, gives a mean of north-west at 12 knots with mean gusts of 29 knots. That is breezy year-round, not only in meltemi season. Any page describing Santorini as flat calm is describing a good morning, not a climate.

How rough is the water?

Inside the caldera the cliffs block much of the wind and the water is usually calm. Outside, around the south and west coasts, it can be choppier, especially in the afternoon once the meltemi has built. Mornings are typically the flatter sailing, which is why our day cruise leaves at 10:00.

When is the meltemi strongest in Santorini?

July and August, when it is near-continuous, with the peak running from about mid-July to mid-August. Within a single day, it is strongest in mid-afternoon and weakest overnight and in the early morning. It can appear from late May and linger into October, but rarely with the same persistence.

Is August a bad month for a Santorini boat tour?

It is the warmest water of the year at about 24.5 °C, and the roughest average afternoons. Neither cancels the other out. If you are coming in August, take a morning departure, book a date early in your stay, and keep one spare day in reserve. That combination works.

Does the meltemi affect ferries as well as boat tours?

Yes. Guides covering the best time to visit note that the meltemi peaks in July and August and can shut ferry services down outright. Small boats stop before large ones do. If your plans depend on a ferry connection either side of a cruise, build slack into the day.

Which month has the calmest sea for a boat tour?

September is the usual answer, and it is a good one. The meltemi weakens through the month, the sea is still about 24 °C, and the afternoon build is milder than in August. May and early June are the other quiet window, with a cooler sea and fewer boats anchored in the same bays.

Santorini Boat Tour - Water Taxi is a catamaran cruise and water taxi operator based in Fira, Santorini.

Updated August 2026